Long-term zinc and iron supplementation in children of short stature: Effect of growth and on trace element content in tissues

We evaluated the effect of one year of supplementation with iron plus zinc (12 mg /day of Fe+++ and 12.5 mg/day of Zn++), zinc alone (12.5 mg/day of Z n++) and placebo on growth and on the iron, zinc, copper and selenium tissu e contents in 30 well-selected children of short stature (16 M and 14 F; 4- 11 years old). Before and after supplementation, we measured the concentrat ions of iron, transferrin, ferritin, zinc and copper in serum, of zinc in e rythrocytes and leukocytes, and of zinc, copper and selenium in hair, as we ll as glutathione peroxidase activity in erythrocytes. Before supplementati on, ferritin and serum, erythrocyte and hair zinc contents were significant ly lower than in age-matched controls, while the other measured indices wer e in the normal range. Iron plus zinc supplementation caused an improvement in growth rate in all subjects, i.e., the median Z-score increased from -2 .22 +/- 0.45 to -0.64 +/- 0.55; (p < 0.01). In the zinc-supplemented group, only the subjects whose ferritin levels were higher than 20 ng/L before su pplementation showed a similar improvement of growth rate. Iron plus zinc s upplementation could be a reasonable treatment in short, prepubertal childr en affected by marginal zinc and iron deficiency.